Nightmare Galaxy has been to gravity falls before when she was thirteen, where she meet Mabel, Dipper, Bill, Mabel Gleeful and her twin Dipper Gleeful and Will Cipher, who had developed a deadly obsession for her, but she managed to escape. Now four years later, Nightmare has completely forgotten them and doesn't even remember, due to the fact she chose not too. Now seventeen and with powers and being famous, she's heading to gravity falls for the summer where some old faces turn up and this time, they'll make sure she never leaves